Remove global call sets: regcprop.c

Remove global call sets: regcprop.c

This is a direct replacement of an existing test for fully and
partially clobbered registers.

2019-09-30  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* regcprop.c (copyprop_hardreg_forward_1): Use the recorded
	mode of the register when deciding whether it is no longer
	available after a call.

From-SVN: r276331